I point this out because the SoCG proceedings were managed by LIPIcs, the Leibniz International Proceedings in Informatics. I've been on the editorial board for LIPIcs for several years. The goal was to establish an open but professional publication mechanism that would be affordable in comparison to what was being offered by standard publishing programs. From the announcement in 2009:
Schloss Dagstuhl Leibniz Center for Informatics (LCI) establishes a new series of conference proceedings called Leibniz International Proceedings in Informatics (LIPIcs). The objective of this series is to publish the proceedings of high-quality conferences in all fields of computer science, and LCI institutes an Editorial Board to oversee the selection of the conferences to be included in this series.
The proceedings in the LIPIcs series will be published electronically and will be accessible freely and universally on the internet, keeping the copyrights of the authors, and under an open access license guaranteeing free dissemination. To face the cost of electronic publication, a one-time fee will be required from the conference organizers. This fee will be kept to a minimum, thought to cover the costs of LCI, thanks in particular to a sharing of the workload between LCI and the conference organizers.
LIPIcs has been, I think, growing in visibility and success, in terms of attracting more conferences. If you're looking for a different approach to publishing proceedings for your conference that seems more in line with what many I've heard want from their conference proceedings, I encourage you to take a look. It may not be for everyone, but we expect it may be useful for more conferences than are currently using it.